I have a duck that has been sitting on a nest of eggs for 22 days. She laid around 10 eggs, but a chicken had laid a few eggs there also. Yesterday one of the chicken eggs hatched. Cute little yellow chick. The duck is still sitting on eggs and the chick runs under her also. The problem is that I do not know if the duck eggs are fertile, I bought a drake around the same time she started to sit. I know that duck eggs will take about a week longer to hatch if they are fertile. What to do? Wait a few more days to see if another chick hatches, or remove the chick and buy a few more chicks so the chick will have company. If the duck eggs are not fertile, can I remove them and buy some day old duckling and try to trick the duck into thinking they hatched from her eggs?